Android is a great mobile OS, even at the stage it's at now. It won't be surprised if at one point it's running on more phones than the iPhone OS.
My girlfriend is developing an application for the platform. It's open source. The SDK is available and free. They're even providing grants for developers.
Here's the Google overview video:
https://youtube.com/watch?v=1FJHYqE0RDg
http://code.google.com/android/